PC/Mobile
PC A personal computer (PC) is a multi-purpose computer whose size, capabilities, and price make it feasible for individual use. PCs are intended to be operated directly by an end user, rather than by a computer expert or technician. Computer time-sharing models that were typically used with larger, more expensive minicomputer and mainframe systems, to enable them be used by many people at the same time, are not used with PCs. Early computer owners in the 1960s, invariably institutional or corporate, had to write their own programs to do any useful work with the machines. In the 2010s, personal computer users have access to a wide range of commercial software, free software ("freeware") and free and open-source software, which are provided in ready-to-run form. Software for personal computers is typically developed and distributed independently from the hardware or OS manufacturers.1 Many personal computer users no longer need to write their own programs to make any use of a personal computer, although end-user programming is still feasible. This contrasts with mobile systems, where software is often only available through a manufacturer-supported channel, and end-user program development may be discouraged by lack of support by the manufacturer. Since the early 1990s, Microsoft operating systems and Intel hardware have dominated much of the personal computer market, first with MS-DOS and then with Windows. Alternatives to Microsoft's Windows operating systems occupy a minority share of the industry. These include Apple's macOS and free open-source Unix-like operating systems such as Linux. Advanced Micro Devices (AMD) provides the main alternative to Intel's processors. Mobile Phone A mobile phone, known as a cell phone in North America, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area. The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network (PSTN). Modern mobile telephone services use a cellular networkarchitecture, and, therefore, mobile telephones are called cellular telephones or cell phones, in North America. In addition to telephony, 2000s-era mobile phones support a variety of other services, such as text messaging, MMS, email, Internet access, short-range wireless communications (infrared, Bluetooth), business applications, video games, and digital photography. Mobile phones offering only those capabilities are known as feature phones; mobile phones which offer greatly advanced computing capabilities are referred to as smartphones. The first handheld mobile phone was demonstrated by John F. Mitchell12 and Martin Cooper of Motorola in 1973, using a handset weighing c. 2 kilograms (4.4 lbs).3 In 1979, Nippon Telegraph and Telephone (NTT) launched the world's first cellular network in Japan.4 In 1983, the DynaTAC 8000x was the first commercially available handheld mobile phone. From 1983 to 2014, worldwide mobile phone subscriptions grew to over seven billion, penetrating virtually 100% of the global population and reaching even the bottom of the economic pyramid.5 In first quarter of 2016, the top smartphone developers worldwide were Samsung, Apple, and Huawei (and "smartphone sales represented 78 percent of total mobile phone sales").6 For feature phones (or "dumbphones") as of 2016, the largest were Samsung, Nokia, and Alcatel.7